Meaning: "endless" means without limit.

Wrong options:

• endles: It leaves out the "s". Check the letters: "endless". A small spelling mistake loses the mark.

Correct answer: curiosity

Explanation: On the recording you hear "innate curiosity to understand". It comes after "innate", so you need a word for a thing.

Meaning: "curiosity" means a desire to learn or know.

Wrong options:

• curiousity: It adds an extra "u". The right spelling is "curiosity". Every letter must be correct to get the mark.

Correct answer: propulsion

Explanation: Listen again to "advanced propulsion technologies". It comes before "technologies", so you need a word for a thing.

Meaning: "propulsion" means the system that moves a craft forward.

Wrong options:

• propultion: It has "t" where the word has "s". Write "propulsion". Only the exact spelling gets the mark.

Correct answer: worlds

Explanation: Here you hear "distant worlds in our". "Distant" is before it, so you need more than one and add s.

Meaning: "worlds" means planets or places beyond Earth.

Wrong options:

• world: "world" has no "s" at the end. The speaker says "worlds", so write the "s".

Correct answer: harbor / harbour

Explanation: The speaker says "could potentially harbor extraterrestrial life". The sentence needs an action word after "potentially". You can write "harbor" or "harbour". Both get the mark.

Meaning: "harbor" means to have or hold, in this case life may exist there.